Academic Credentials
  • Ph.D., Mechanical and Aerospace Engineering, Princeton University, 2002
  • B.E., Mechanical Engineering, Cooper Union, 1996
Licenses & Certifications
  • Professional Engineer Fire, California, #1724
  • Professional Engineer Mechanical, California, #32771
  • Professional Engineer, Colorado, #PE.0045809
  • Professional Engineer Mechanical and Fire Protection, Idaho, #P-15956
  • Professional Engineer, Nevada, #21098
  • Professional Engineer Mechanical, Texas, #153118
  • 40-Hour Hazardous Waste Operation and Emergency Response Certification (HAZWOPER)
  • Certified Fire Investigator (CFI)
  • Certified Forklift Operator (CFO)
  • FI-210 Bridge/Refresher Course on 2014 updates
  • FI-210, Wildland Fire Origin and Cause Determination
  • Fire Investigation 1A (Cause and Origin), California Office of State Fire Marshal
  • Fire Investigation: Techniques of Fire Investigation (1B), California State Fire Marshall
  • Industrial Furnaces and Ovens Safety Standards Training
Professional Honors
  • Guggenheim Merit Fellowship, Princeton University, 1996
  • William C. and Esther Hoffman Beller Prize in Mechanical Engineering, The Cooper Union, 1996
Professional Affiliations
  • [2014 – Present] Principal Member: Technical Committee on Wildland and Rural Fire Protection, NFPA 1141 Standard for Fire Protection Infrastructure for Land Development in Wildland, Rural, and Suburban Areas; and NFPA 1142 Standard for Water Supplies for Suburban and Rural Firefighting; NFPA 1144 Standard for Reducing Structure Ignition Hazards from Wildland Fire, National Fire Protection Association
  • [2010 – Present] Principal Member: Technical Committee on Industrial and Medical Gases, NFPA 51 Standard for the Design and Installation of Oxygen-Fuel Gas Systems for Welding, Cutting, and Allied Processes; NFPA 51A Standard for Acetylene Cylinder Charging Plants; NFPA 55 Standard for the Storage, Use, and Handling of Compressed Gases and Cryogenic Fluids in Portable and Stationary Containers, Cylinders, and Tanks; and NFPA 560 Standard for the Storage, Handling, and Use of Ethylene Oxide for Sterilization and Fumigation, National Fire Protection Association
  • [2004 – 2018] Principal Member: Technical Committee on Ovens and Furnaces, NFPA 86 Standard for Ovens and Furnaces, National Fire Protection Association
  • [2010 – 2018] Principal Member: Technical Committee on Fluid Heaters, NFPA 87 Recommended Practice for Fluid Heaters, National Fire Protection Association
  • National Fire Protection Association (member)
  • International Association of Wildland Fire (member)

Dr. Christiansen specializes in fire science, combustion chemistry, fluid mechanics, thermodynamics, and heat transfer. He performs origin and cause investigations of fires and explosions, ranging from small residential fires to large-scale industrial incidents to multi-acre wildland fires. 

Dr. Christiansen has investigated numerous vehicle related fires, including passenger cars, recreational vehicles, and on- and off-highway trucks, as well as fires in marine vessels such as recreational boats, cruise ships and large shipping vessels. He also investigates thermal related failures of consumer appliances; commercial and residential cooking equipment; and heating, ventilation, air-conditioning, and refrigeration (HVAC&R) systems.

Dr. Christiansen's project experience also includes natural gas and propane appliances and systems, oxygen equipment, welding and hot work activities, industrial ovens, furnaces and boilers, runaway chemical reaction (spontaneous combustion), burn injuries, carbon monoxide (CO) exposure, and fire and building code review. Additionally, he performs engineering analysis of fire protection systems, including the design, testing, and operation of automatic fire sprinkler systems and dry and wet chemical fire suppression systems. Dr. Christiansen has testified as an expert witness in state and federal court on various occasions. 

Prior to joining Exponent, Dr. Christiansen was a research assistant in the Combustion and Energy Laboratory at Princeton University where he conducted research on the effects of flame instabilities on extinction and the limits of flammability.